The present invention relates to pulse tube coolers, and more particularly, to an improved pulse tube cooler having a insulated concentric pulse tube expander.
A linear pulse tube cooler is arranged such that all components of its expander are disposed in a linear fashion. Consequently, two warm heat exchangers are disposed at opposite ends of the expander and a cold station is disposed in the middle. Packaging using linear pulse tubes is therefore awkward.
A concentric pulse tube cooler has one integrated warm heat exchanger disposed at one end of the expander, and a cold station is disposed at the opposite end of the expander in a conventional fashion. The concentric pulse tube expander is easier to package, install, use and is smaller than current linear pulse tube coolers.
Conventional concentric pulse tube expanders have not incorporated an insulator between the pulse tube and the regenerator. It was assumed that the temperature gradient and heat distribution in the pulse tube and the regenerator were similar.